EES Seminar Series, "Comparing the impact of tropical and high latitude volcanic eruptions on global temperatures and precipitation"

Fri, 02/16/2018 - 10:00am

105 Memorial Hall

The Department of Earth and Environmental Sciences, University of Windsor is pleased to announce:

"Comparing the impact of tropical and high latitude volcanic eruptions on global temperatures and precipitation"

presented by Paul Sotiriou, PhD Candidate
on

Friday, February 16, 2018
at
10:00 am
105 Memorial Hall

AbstractLarge volcanic eruptions can inject large quantities of aerosols into the stratosphere. Eruptions with a volcanic explosivity index (VEI) value of >4 are thought to play a key role in the stratospheric sulphate aerosol budget. Furthermore, explosive volcanism is known to be a leading natural cause of climate change. Equatorial volcanic eruptions have been widely studied for their significant contribution to stratospheric aerosol loading and global climate impacts.

A number of large volcanic eruptions (Pinatubo, 1991; Krakatoa, 1883; Mount Tambora, 1815, Laki, 1783-84) have had a profound impact on global climate over the last 250 years and evidence suggests that equally profound eruptions have occurred further back in history (e.g., Samalas, 1257-58). All but one of these high climatic impact eruptions (Laki, Iceland) occurred near the equator and, not surprisingly, low-latitude, tropical volcanic eruptions have been more widely studied for their momentous contribution to global climate.

There is a longstanding perception that tropical volcanic eruptions have had a greater impact on global precipitation and both land and sea surface temperatures, perhaps fuelled by the occurrence of a number climatically significant eruptions in this region in the last 250 years. More recent evidence suggests that high-latitude eruptions can also have a significant impact on global climate. As such, there is some uncertainty about whether tropical or high-latitude volcanic eruptions have had a more profound impact on global climate.

Studies by D'Arrigo et al. (2008) and Schneider et al. (2009) used a fully coupled NCAR Community Climate System Model (CCSM3) and a composite tropical (30°N-30°S) sea surface temperature reconstruction, respectively. They found that tropical volcanic eruptions have a more profound impact on global land and sea surface temperatures. In contrast, studies by Liu et al. (2016) and Wu et al. (2017) indicate that high-latitude volcanic eruptions have a significant impact on global monsoon precipitation. These conclusions were based on using a 1500 year volcanic sensitivity simulation by the Community Earth System Model v.1.0 (CESM1) and observations and simulations, respectively.

Tropical volcanic eruptions have had a more profound impact on global land and sea surface temperatures than high-latitude volcanic eruptions. High-latitude volcanic eruptions in the both the Northern Hemisphere and the Southern Hemisphere, in contrast, have a more significant impact on global monsoon precipitation than tropical eruptions. Both tropical and high-latitude volcanic eruptions have a profound impact on global climate, the former greatly impacting global land and sea surface temperatures and the latter impacting global monsoon precipitation.